Terry Perciante

This third and final volume of Strategic Activities on fractal geometry and chaos theory focuses upon the images that for many people have provided a compelling lure into an investigation of the intricate properties embedded within them. By themselves the figures posses fascinating features, but the mechanisms by which they are formed also highlight significant approaches to modeling natural processes and phenomena. The general pattern and specific steps used to construct a fractal image illustrated throughout this volume, comprise an iterated function system. The objective of this volume is to investigate the processes and often surprising results of applying such systems. These strategic activities have been developed from a sound instructional base, stressing the connections to the contemporary curriculum as recommended in the National Council of Teachers of Mathematics' Curriculum and Evaluation Standards for School Mathematics. Where appropriate, the activities take advantage of the technological power of the graphics calculator. The contents of this volume joined with the details contained in the prior two books. Together they provide a comprehensive survey of fractal geometry and chaos theory. The dynamic nature of the research and the experimental characteristics of related applications provides an engaging paradigm for classroom activity.

Das vorliegende Arbeitsbuch ist Teil eines Paketes von verschiedenen Materialien, die das Ziel haben, das Thema Chaos und Fraktale in den mathematisch-naturwissenschaftlichen Unterricht einzuführen. Ein weiteres Anliegen besteht darin, das mentale Bild von Mathematik im Bewußtsein der Schüler attraktiver zu gestalten. Mathematik ist die Antwort des Menschen auf die Komplexität der Welt. Mathematik ist die Ordnungsmacht im Dschungel der Phänomene. Deshalb ist Mathematik le­ bendig, frisch und aktuell. Deshalb gibt es zwischen einzelnen Teilgebieten und Ergebnissen der Mathematik immer wieder überraschende Querverbindungen, die oft das Verständnis einer Sache erst wirklich erhellen. Und deshalb bietet es sich an, durch entdeckendes, explorierendes Lernen die Anziehungskraft dieser Eigenschaften der Mathematik im Unterricht auszunutzen. Chaos und Fraktale bieten hierfür eine besondere neue Chance. Beide sind jung und aktuell und belegen so ohne weiteres, daß Mathematik lebt. Für beide gilt, daß einige ihrer schrittmachenden Entdeckungen nicht ohne Hilfe von Computern möglich gewesen wären. Damit rücken faszinie­ rende Computerexperimente natürlich in den Mittelpunkt. Beide sind hochgradig interdisziplinär. Dieses heißt, daß gehaltvolle Anwendungen nicht erst mühsam konstruiert werden müssen. Beide behandeln Themen, die von sich aus wirken. Tatsächlich durchlaufen seit Ende der siebziger Jahre Mathematik und Naturwissenschaften eine Welle, die in ihrer Kraft, Kreativität und Weiträumigkeit längst ein interdisziplinäres Ereignis er­ sten Ranges geworden ist. Das andauernde Interesse innerhalb und außerhalb der Wissenschaften ist in einer aufrüttelnden Betroffenheit begründet, die eine radikale Wende in dem überkommenen naturwissenschaftlichenWeltbild und manchen überdehnten Interpretationen ankündigt.

The same factors that motivated the writing of our first volume of strategic activities on fractals continued to encourage the assembly of additional activities for this second volume. Fractals provide a setting wherein students can enjoy hands-on experiences that involve important mathematical content connected to a wide range of physical and social phenomena. The striking graphic images, unexpected geometric properties, and fascinating numerical processes offer unparalleled opportunity for enthusiastic student inquiry. Students sense the vigor present in the growing and highly integrative discipline of fractal geom­ etry as they are introduced to mathematical developments that have occurred during the last half of the twentieth century. Few branches of mathematics and computer science offer such a contem­ porary portrayal of the wonderment available in careful analysis, in the amazing dialogue between numeric and geometric processes, and in the energetic interaction between mathematics and other disciplines. Fractals continue to supply an uncommon setting for animated teaching and learn­ ing activities that focus upon fundamental mathematical concepts, connections, problem-solving techniques, and many other major topics of elementary and advanced mathematics. It remains our hope that, through this second volume of strategic activities, readers will find their enjoyment of mathematics heightened and their appreciation for the dynamics of the world in­ creased. We want experiences with fractals to enliven curiosity and to stretch the imagination.

There are many reasons for writing this first volume of strategic activities on fractals. The most pervasive is the compelling desire to provide students of mathematics with a set of accessible, hands-on experiences with fractals and their underlying mathematical principles and characteristics. Another is to show how fractals connect to many different aspects of mathematics and how the study of fractals can bring these ideas together. A third is to share the beauty of their structure and shape both through what the eye sees and what the mind visualizes. Fractals have captured the attention, enthusiasm, and interest of many people around the world. To the casual observer, their color, beauty, and geometric structure captivates the visual senses like few other things they have ever experienced in mathematics. To the computer scientist, fractals offer a rich environment in which to explore, create, and build a new visual world as an artist creating a new work. To the student, fractals bring mathematics out of past history and into the twenty-first century. To the mathematics teacher, fractals offer a unique, new opportunity to illustrate both the dynamics of mathematics and its many connecting links.